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authorRob Clark <robdclark@chromium.org>2022-08-02 18:51:42 +0300
committerRob Clark <robdclark@chromium.org>2022-08-27 19:32:45 +0300
commite7c2af13f811d0c23340154b7b2795876c71e4be (patch)
tree85b5ab9a44e2a89d5169682b893879c23a267944 /include/drm
parentda53d8b54647482125e29ef80dd9acbb64f2d67f (diff)
downloadlinux-e7c2af13f811d0c23340154b7b2795876c71e4be.tar.xz
drm/gem: Add LRU/shrinker helper
Add a simple LRU helper to assist with driver's shrinker implementation. It handles tracking the number of backing pages associated with a given LRU, and provides a helper to implement shrinker_scan. A driver can use multiple LRU instances to track objects in various states, for example a dontneed LRU for purgeable objects, a willneed LRU for evictable objects, and an unpinned LRU for objects without backing pages. All LRUs that the object can be moved between must share a single lock. v2: lockdep_assert_held() instead of WARN_ON(!mutex_is_locked()) v3: make drm_gem_lru_move_tail_locked() static until there is a user Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Thomas Zimmermann <tzimmermann@suse.de> Cc: Dmitry Osipenko <dmitry.osipenko@collabora.com> Signed-off-by: Rob Clark <robdclark@chromium.org> Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Patchwork: https://patchwork.freedesktop.org/patch/496128/ Link: https://lore.kernel.org/r/20220802155152.1727594-10-robdclark@gmail.com
Diffstat (limited to 'include/drm')
-rw-r--r--include/drm/drm_gem.h55
1 files changed, 55 insertions, 0 deletions
diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
index 87cffc9efa85..f28a48a6f846 100644
--- a/include/drm/drm_gem.h
+++ b/include/drm/drm_gem.h
@@ -175,6 +175,41 @@ struct drm_gem_object_funcs {
};
/**
+ * struct drm_gem_lru - A simple LRU helper
+ *
+ * A helper for tracking GEM objects in a given state, to aid in
+ * driver's shrinker implementation. Tracks the count of pages
+ * for lockless &shrinker.count_objects, and provides
+ * &drm_gem_lru_scan for driver's &shrinker.scan_objects
+ * implementation.
+ */
+struct drm_gem_lru {
+ /**
+ * @lock:
+ *
+ * Lock protecting movement of GEM objects between LRUs. All
+ * LRUs that the object can move between should be protected
+ * by the same lock.
+ */
+ struct mutex *lock;
+
+ /**
+ * @count:
+ *
+ * The total number of backing pages of the GEM objects in
+ * this LRU.
+ */
+ long count;
+
+ /**
+ * @list:
+ *
+ * The LRU list.
+ */
+ struct list_head list;
+};
+
+/**
* struct drm_gem_object - GEM buffer object
*
* This structure defines the generic parts for GEM buffer objects, which are
@@ -312,6 +347,20 @@ struct drm_gem_object {
*
*/
const struct drm_gem_object_funcs *funcs;
+
+ /**
+ * @lru_node:
+ *
+ * List node in a &drm_gem_lru.
+ */
+ struct list_head lru_node;
+
+ /**
+ * @lru:
+ *
+ * The current LRU list that the GEM object is on.
+ */
+ struct drm_gem_lru *lru;
};
/**
@@ -420,4 +469,10 @@ void drm_gem_unlock_reservations(struct drm_gem_object **objs, int count,
int drm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
u32 handle, u64 *offset);
+void drm_gem_lru_init(struct drm_gem_lru *lru, struct mutex *lock);
+void drm_gem_lru_remove(struct drm_gem_object *obj);
+void drm_gem_lru_move_tail(struct drm_gem_lru *lru, struct drm_gem_object *obj);
+unsigned long drm_gem_lru_scan(struct drm_gem_lru *lru, unsigned nr_to_scan,
+ bool (*shrink)(struct drm_gem_object *obj));
+
#endif /* __DRM_GEM_H__ */